


/3 




MAR 7 



REPORT 



ELECTRICAL METHOD OF 
THAWING WATER PIPES 



BY 

GEO. S. HALEY 



DECEMBER i, 1904 



published by order of the 

National Electric Light Association 

new york city 



Gift 



Carnegie In§t. 
Handbook Office 

tO ApJ90iT 



«6 



ELECTRICAL METHOD OF THAWING WATER 

PIPES 



A large number of electric light companies have, for the 
past few years, found a new field for the use of their product, 
which adds materially to their revenue, and particularly to the 
comfort of the citizens of their respective cities — that of thaw- 
ing frozen water services by the use of electric current. 

The fact that the methods are not generally known has 
induced the president of the National Electric Light Associa- 
tion to authorize the publication of this report, which will be 
distributed to all our central-station members in those portions of 
the United States and Canada that are afflicted by a climate 
that congeals the earth to a depth equal to that of the aver- 
age water system. 

From information gathered, your reporter believes that the 
first application of this method of thawing water pipes — thereby 
depriving the plumber of his proverbial ill-gotten gains and 
possibly transferring them to one equally covetous in the opin- 
ion of the public — was made at Madison, Wis., by Professors 
R. W. Wood and D. C. Jackson during the winter of 1898 
and 1899. 

During the extreme cold weather, many water services wxre 
frozen in the city of Madison, Wis. The plumbers were unable 
to cope with the prevailing conditions, and it was then that Pro- 
fessor Wood conceived the idea of thawing frozen water pipes 
by electric current. He consulted with Professor Jackson and 
in connection with the local company, which provided the neces- 
sary apparatus, probably thawed the first pipe by the use of 
electric current. The plan was so successful that they imme- 
diately began to do this work on a wholesale basis and during 
that winter thawed out a large number of service pipes N A 
number of cities in the immediate neighborhood called for infor- 
mation concerning this method, which was furnished, and in 
some cases when assistance was called for, some of the senior 
students of the University of Wisconsin were sent out. 

Aside from the remarkablv clean and effective manner in 



/6~26'< 



which the electric outfit does its work, no other method being 
in my estimation near enough for comparison, the value to 
insurance companies must be worth considering, From a 
reliable source, I find that during the year of 1898 insurance 
companies paid about $300,000 in losses caused by fires started 
by other methods of thawing water pipes. Every one is familiar 
with the usual methods of thaw T ing pipes practiced by plumbers, 
and when digging has to be resorted to it is a very expensive 
proposition and even plumbers are justified in rendering the 
enormous bills credited them. 

In order to facilitate the compilation of facts, circulars 
containing the following questions were mailed to about one 
thousand of the large central stations in the northern part 
of the United States and Canada. About two hundred replies 
have been received. Seventy-five of these are from companies 
that have already used the electrical method of thawing pipes 
with apparent success, which would indicate that only a small 
percentage of the electrical companies have had occasion to 
use or have availed themselves of this branch of the electrical 
industry, it being assumed that the majority of those who have 
used this method have taken the trouble to reply. Tabulated 
answers in detail to the most important questions will be found 
on page 18. Under "Abstracts," answers to questions are 
given in a general way, which indicate the opinion of the 
majority of correspondents and other information that could 
not be placed in the tabulated answers. 

QUESTIONS 

1. Have you employed this method of thawing frozen 
water pipes? 

2. Were you asked by your superintendent of water- 
works or by residents of your city to do this work? 

3. Why did you not make the attempt? 

4. W^as it paid for by the city water-works, or by pri- 
vate individuals? 

5. How did you charge for this work? 

a. By a lump sum per service? 

Give rate for average, and other charges for 
special work, if any. 



b. On time and material basis? 
What profit on labor? 
How much per kw-hour? 

Who paid for wear and tear of material and 
apparatus ? 

6. How did you ascertain current consumed? 

Give detailed description of ammeter, voltmeters, or 
wattmeters, used for this purpose. 

7. What voltage was used? 

a. Was current alternating current or direct 

current ? 

b. Is 50 volts alternating current sufficient for 

average house service ? 

8. How did you control the amount of current required 
to heat the pipe? 

a. With rheostat in secondary? 

Give detailed description of same. 
If water rheostat, what was used for elec- 
trodes ? 

b. With choke coils or rheostat in primary? 
Give detailed description ; i. e., windings, size 

and length of wire, size of core, approxi- 
mate cost, et ccetera. 

9. What type of transformer was used? 

a. Give voltage of primary and secondary. 

b. Give capacity in kilowatts used. 

10. Would you purchase a special transformer made for 
the purpose, with primary 1000 to 2000 and secondary o to 
100? 

a. What capacity, maximum, in kilowatts would 

you want ? 

b. How much could you afford to pay for such 

a transformer? 

c. Could you induce your city to purchase or 

carry the investment of a transformer to be 
used for this work, and for them exclusively? 

11. What size of wire was used for secondary feeders? 
If special connectors for attaching wire to faucets or 

mains were used, please describe them. 

a. Were you particular to keep your primaries 
on glass ? 



12. Did you thaw out street mains or hydrants? 

Give size and length of pipe, amperes, volts, and time 
consumed. 

13. Do you know of any damage done to service pipes 
or mains by the use of excessive current? 

a. Give description of pipes, joints, et cater a, 
damaged. 

14. Was the vehicle used to move the apparatus made 
especially for the purpose, or was it adapted from something 
you had or purchased? 

a. Give description of any desirable features it 

may have. 

b. What did it cost? 

Send photographs of apparatus, if possible. 

15. Do you consider the work especially hazardous? 

a-. Should this be taken into consideration when 
charging for services rendered? 

16. Were your efforts appreciated by those directly con- 
nected with the water-works and their patrons? 



A FEW POINTS FOR THE BEGINNER 

As to the method of procedure to thaw with electric cur- 
rent, assuming an alternating current of one or two thousand 
volts is available, the necessary requisites are as follows : 

1. A transformer of 10 or 15-kilowatt capacity with 50 
and 100-volt secondary; for ordinary house services 50 volts 
is sufficient. 

2. An ammeter reading, to 30 amperes if placed in the 
primary. 

3. Primary cutouts. 

4. Single-pole switch in secondary. 

5. A resistance that can be made as described in Figure 7. 
Connect up instrument as shown in Figure 1, leaving the 

movable electrode out of the water. Close the primary switch 
and drop the lower end of the electrode into the water, watch- 
ing the ammeter, which should indicate 3 to 5 amperes and 
which will increase as the electrode is given more contact with 
the water; the maximum amount of current will depend on the 
resistance of the pipe. By consulting the tables attached the 









i 



amounts of current required for different services, mains, et 
c cetera, also the length of application, may be approximated. 
The most practical arrangement, aside from a transformer made 
for the purpose, is shown in Figure 2. 

A choke coil, made as described in connection with Fig- 
ure 6 and placed between the primary switch and the trans- 
former, gives practically the same results and is much more 
efficient and easier handled. 

Before closing the secondary switch, the position of the 
core of the choke coil should be noted. It should be completely 
inside the choke coil, and to increase the secondary current, 
withdraw it until the required amperes are obtained. 

The following diagrams and photographs show connec- 
tions necessary to apply the electric current for the purpose 
of thawing frozen water pipes ; also some of the different appli- 
ances used in connection with this work. 

Figure 1 shows two house services being thawed at the 
same time, one end of each secondary being attached to the 
sillcock of each house, the resistance R being placed in the sec- 





n 








O 


■r. 


> 


c 


O 


■?, 


H 


& 


m, 









c 


< 


g 




1— 1 



-o- 

Fuses 

-o- 



House 



<£> 



WWVWW 

IWVW1 



House 



Water Main 



Fig. 1 



ondary circuit. Ammeter A indicates the number of amperes 
in the primary circuit. The transformer should be protected 
by suitable fuses, located either upon the pole adjacent to the 
primary feeders or upon the wagon. 



Figure 2 shows one house service being thawed and con- 
nected to one side of the secondary feeder, the other being 
connected to hydrant H. In the diagram, A represents the 





Fig. 2 



ammeter in the primary circuit, M, a recording wattmeter in 
the secondary, and V a voltmeter connected across the secondary 
terminals of the transformer. 

Figure 3 shows a connection for the use of 104 to 125 
volts, alternating or direct current. This arrangement is 



o 

to b> 







o 



& 



Fuses 

^D ®- 



\ s 



House 



Water Mai* 



Fig. 3 



applicable to isolated plants using two or three-wire low-volt- 
A indicates the ammeter and R the resistance. 



age distribution 



Figure 4 shows the simplest outfit possible : a 10-kilowatt 
transformer connected for 104 volts, an ammeter and switch 
in the secondary, and fuse boxes in the primary either on the 
wagon or on the pole near the point of connection to the pri- 




Fjg. 4 



mary feeders. While the outfit will do the work, I would 
advise by all means the use of a resistance of some kind in 
order to control the quantity of current at the start. 

Figure 5 is a photograph of an outfit used at Gloversville, 
N. Y. A simple rack is built upon the body of the sled upon 
which are placed the primary cutouts. The primary wires are 
dropped from the pole to the top of this frame work, then to 
the cutouts. The current is measured by the wattmeter shown 
which is connected in the secondary circuit. Standard trans- 
formers are used, connections made as described in Figure 
9, which give a sufficient range of voltage. The wires used for 



primaries and secondaries are mounted upon reels in a con- 
venient manner for easy handling. For a cheap and effective 




_ 



Fig 5 



outfit, this seems to be the most practical that has been sug- 
gested. 



Figure 6 shows a choke coil suitable to control for all 
purposes a 15 or 20-kilowatt transformer with 2000 volts pri- 
mary, and is constructed as follows : 

A tube 16 inches long, 2 inches in diameter, made by wind- 
ing a sheet of one-sixteenth inch red fibre around an iron 
mandrel four times and held in place by a few small tacks ; 
two wooden beads are provided, six inches in diameter by three- 
quarters of an inch thick, and secured to the ends of the fibre 





300 turiwTia W.P. wire %^> 


<- 






4 




, , + „..- . 


















Fig. 6 

tube. A winding consisting of 200 turns of No. 12 weather- 
proof wire is placed on the spool after it has been given several 
coats of shellac and dried. A core is made of No. 14 iron 
wire in pieces 16 inches long, held together by a few turns of 
fine iron wire and covered by two layers of tape. The centre 
wires are cut four inches longer, and over them is placed a 
wooden handle. 




Fig. 7 



Figure 7 illustrates the simplest form of rheostat suitable 
for either primary or secondary, but recommended for second- 



ary sides only, because of safety to those using it. It is a barrel 
of water to which 10 pounds of common salt has been added, 
with two electrodes, each made of a coil of 10 feet of No. 2 
bare copper wire in a flat spiral, or a six-inch pipe flange, one 
fastened to the side of the barrel near the bottom, the other 
so arranged that it can be raised or lowered. The cut shows 
such an arrangement, which may, of course, be elaborated 
upon according to the ideas of the user. This form of resist- 
ance has been used by the majority of those who have thawed 
pipes by electric current, probably because it was the easiest 
obtained; and while not strictly up-to-date, electrically speak- 
ing, it certainly answers the purpose. A rheostat of this 
description will handle 300 amperes for a short time; if con- 
tinued, the water will probably boil over. 

Figure 8 shows a connection used by one correspondent 
using an ordinary transformer, wound for 1000 and 2000 volts 



-1000 -V4- 



1 2 



X) 



wwvvv vwwv 

/wwvw\ 



17y 2 to 50 
Fig. 



primary, and used upon a 1000- volt circuit; the secondary volt- 
age is 50. A and 4 on the diagram indicate the fuse plugs 
in the primary circuit; 1-2-3 indicate plug cutouts, having but 
one plug for all three; B is a plug used to short-circuit the 
choke coil. While manipulating plugs 1-2-3 and the choke coil 
the correspondent states that any voltage between 17.5 and 50 
is obtainable. It would seem that sufficient variation should be 



obtained either by the use of the choke coil or by the changing 
of the connections in the transformer. 

Figure 9 indicates connections of standard transformers 
giving the voltage from 22 volts to 220. A 5-kw transformer 
is connected to the 2200-volt primary ; the secondary is 220 volts, 
and feeds the primaries of two 15-kw transformers. The ratio 
is one to five, their secondaries being connected in multiple. 



2200 Volts 



5 KW. 

2200 to 220 



ft 



22 Volts 



Fig. 



[5 KW. 




15 KW. 


1100 to 




1100 to 


2a0 




220 



This connection would give 22 volts secondary. By proper 
connections of primary and secondary leads from the different 
transformers, almost any voltage should be obtained up to 220. 
Some judgment should be exercised in the manipulation of this 
arrangement, otherwise the primary coils might be overloaded. 

Figure 10 is a photograph of an outfit used by the New 
York Edison Company, the. current being taken from the sec- 
ondary feeders of their lighting system, controlled and meas- 
ured by rheostats and other necessary instruments mounted 
in a covered auto truck. 

Figure 11 is a photograph of an outfit used in Durango, 
Col., which is the most complete in detail of any that have come 
to our notice. Four small transformers, taken from the scrap 
pile with 55- volt secondaries, were placed in the wagon in front 
of the switchboard. In the secondary of each transformer is 
placed a choke coil, described as follows : 

The choke coils are about 18 inches long with a core 2.5 
inches in diameter, formed on a brass tube with cast ends, a slot 



12 



being cut lengthwise through the tube and ends to prevent the 
formation of a closed secondary circuit in the spool. After 
being thoroughly insulated, each core is wound with two layers 
of No. 4 magnet wire. The cores, which are 18 inches long, 
consist of 500 pieces of No. 14 annealed iron wire, which are 
assembled around a central iron rod, threaded at each end, with 
two fibre heads turned to fit the tube. The whole core is cov- 
ered with several layers of cotton tape, coated with insulating 
varnish. Above each choke coil is placed a 75 -ampere double- 




Fig. 10 



pole knife switch and a 100-ampere double-pole D. & W. cut- 
out; also one 350-ampere ammeter and one 150- volt voltmeter. 
There are also four pilot lamps, one of each being connected to 
the four transformers, which by the switches mentioned can be 
thrown in multiple. On the back of the wagon cover are placed 
two G. E. primary cutouts and just back of these, not shown, 
is a 30-ampere double-pole, quick-break knife switch, placed 
in the primary circuit. The secondary leads are composed of 
No. 00 cable wire with connectors made of brass, to facilitate 



13 

the connections of the pipe system. To use this outfit the pri- 
maries are brought from the pole to the cutouts. The secondary 
connections are made to two houses, or one house and a hydrant. 




Fig. ii 



The primaries and secondaries are then closed and the cores 
pulled out of the choke coil until the desired amount of current 
is obtained. 



14 

Figure 12 illustrates a transformer recently designed by the 
General Electric Company for the purpose of thawing water 
pipes. The following is a partial description taken from a re- 
cent publication on this particular subject: 

The transformer is designed to withstand rough handling 
and outdoor service and is mounted on a cast-iron base, which 
is provided with four broad-flanged wheels. This transformer 
is built for primary voltages from 2000 to 2300 volts, with a 
frequency of 60 cycles. The secondary voltage is readily ad- 




FlG. 12 



justed by means of a hand wheel, shown in the cut, from o to J$ 
volts giving o to 400 amperes. The transformer core has three 
horizontal legs with a closed magnetic circuit at the ends. Flat 
pancake coils are threaded on the middle leg and spaced apart, 
so as to permit an adjustable flux shunt to move up and down 
between the primary and secondary coils. This construction 
affords a simple and convenient method of obtaining any voltage 
and current, from zero to maximum. The leads of the primary 
•coil are brought down to a suitable connection board on the side 






i5 

of the transformer, on which are mounted primary switches, 
fuses and an ammeter. The terminals of the secondaries are 
brought to heavy lugs at the end of the transformer, from which 
cables can be brought to the ends of the pipes to be thawed. 
Such an outfit, including transformer, switches, cover and meter, 
weighs approximately 1200 pounds. The space occupied by the 
transformer is about 20 by 30 inches with a height of 36 inches. 
The transformer is designed to stand a temporary overload of 
100 per cent, giving an output of 800 amperes for a period of 
ten to fifteen minutes of perfect safety. The primary coils, 




Fig. 13 

while designed for 2200 volts, can be safely operated at any volt- 
age from 1500 to 2500, and will be manufactured upon order 
with special primary windings, adapted to voltage limits of 500 
and 3500 volts. This transformer is made in two sizes, 20 and 
30 kilowatts, and will be sold at about the price of the standard 
transformers of the same capacity. To operate this transformer 
the following instructions are given : 

After being located close to the frozen pipes, the flux shunt 
core should be dropped to its lowest position, the secondary 



16 



connected to the water pipe and the primary connected to the 
line. After closing' the primary switch the shunt should be 
raised by means of the operating wheel until sufficient voltage 
and current are obtained for the particular pipe under treat- 
ment. The operating wheel should be clamped by means of a 
thumb screw, provided for that purpose. After the pipe has 




Fig. 14 



been completely thawed, the shunt should again be secured to 
its lowest position, ready for the next. 

Figures 13 and 14 illustrate a transformer made by the 
Pittsburg Transformer Company for the purpose of thawing 
pipes. It is described in a circular recently issued, as follows: 



n 

DESCRIPTION 

The outfit consists of a transformer adapted to operate on 
any circuit of approximately noo or 2200 volts and 60 or 133 
cycles. The transformer will deliver a current of 300 amperes 
continuously, or currents of about 600 amperes for periods of 
half an hour. 

On the back of the transformer are mounted a heat indicator 
and a choke coil. The heat indicator consists of a section of 
lead pipe, connected in series with the transformer, and the 
temperature which this assumes is a guide as to the heating of 
the pipe under treatment. The choke coil consists of a few 
turns of heavy copper bar, with a movable laminated iron core. 
When this plunger 'is pushed entirely into the coil, the trans- 
former secondary may be short circuited, but no more than 
normal current will flow. 

DIRECTIONS FOR USE 

The object is to send current through the frozen section of 
the pipe. One secondary lead should be connected to the pipe 
inside of the house and the other lead connected to a near-by 
hydrant outdoors, or to a pipe inside of a neighboring house. 
Read the following instructions carefully: 

1. Connect transformer to the primary line in the usual 
way, altering the connections on the porcelain terminal block, 
if necessary, to adapt it to your line voltage, as shown on tags 
attached to transformer. 

2. Use any standard fuse blocks to protect transformer. 
Fuse these with a 20-ampere fuse for 11 00- volt circuits or with 
a 10-ampere fuse for 2200 volts. Don't plug in until you are 
ready to operate. 

3. Use about a No. o wire or cable for the secondary 
connections. Put in a switch heavy enough to handle about 
400 amperes. A single-pole switch will do. 

4. Look over your connections carefully. Push plunger 
clear into choke coil, plug in the fuse blocks, and close secondary 
switch. 

5. Keep your hand on the heat indicator and pull out 
plunger little by little until the indicator is hot enough. Water 



i8 

will usually begin to flow slowly in five or ten minutes; let 
it run so as to wash away the remaining ice, and disconnect 
the outfit. 

The weight of this pipe thawer is 235 pounds, which makes 
it very convenient to handle; it will be sold at about the cost 
of a standard 7.5-kw transformer. 

ABSTRACTS FROM LETTERS RECEIVED GIVING PERSONAL IDEAS OF 
CORRESPONDENTS AND OTHER INFORMATION 

Question No. 1. From replies received from the various 
plants throughout the United States and Canada, we learn that 
at least seventy-five electric light and power companies have 
employed this method of thawing frozen pipes. 

Question No. 2. In the majority of cases the superin- 
tendent of the water- works requested this work done. 

Question No. 3. Those that did not make any attempt were 
either not asked to do it, or did not consider it worth while 
to equip an outfit for this work. It is worthy of note that 
almost without exception those who have not already made 
the attempt now want all the information they can get, evi- 
dently just realizing that there is something in it. 

Question No. 4. In the majority of cases the work was 
paid for by the residents or consumers, although in a great 
many instances it was paid for by the water-works company. 

A correspondent states that "where the services were 
frozen between the street main and the curb, the work was 
paid for by the water-works ; when frozen between the curb 
line and the customer's outlet, it was paid for by the consumer. " 

A correspondent writes : "Owing to the discontent among 
the plumbers when we quoted figures to customers direct, we 
finally adopted a plan to do the work for plumbers only, thereby 
relieving ourselves of the trouble caused by bursted water pipes, 
et ccetera. The plumber takes care of this work himself, and 
is required to be on the ground to superintend that portion of 
it." A fixed charge was made of $15 per service connection. 
The amount received by the plumber was not given. 

Question No. 4. A correspondent states that his work 
was properly appreciated by those for whom the work was 
done, but that in his city and other cities in the state, there 
have been complaints and protests made by plumbers against 



their thawing water pipes, as they considered it an infringe- 
ment upon their vested rights. 

A correspondent states that in his opinion it would be 
better for the city to own the electrical apparatus, and when 
not employed for its own use, it could rent it to the plumb- 
ing establishment or to private parties. His company would 
be quite willing to detail a man to make connections to these 
lines, and make a record of current, making a suitable charge 
for the time of the man and current. In other plans, as it has 
found, the company is liable to get into conflict with plumb- 
ing establishments and central labor unions. 

Question No. 5. The price charged for this work is, in 
almost every case, a lump sum, which varies from $2.50 to $25 
per service. As a rule, the smaller towns charge from $2.50 
to $5, generally the latter amount. In the larger cities, the 
prices run from $10 to $25, averaging about $15 per service. 
A few correspondents refused to mention the price they charged 
for the work, but stated that they made it large enough to 
cover the 'cost price and make a fair profit. 

A correspondent states that the company charges a cer- 
tain amount for the first service thawed for one day at one 
setting and if there are more to be thawed on the same day, 
only two-thirds of the price is charged for additional services. 
The charges are based on what it would cost the water-works 
department to thaw an ordinary service by the old method, 
rather than what it actually costs the electric company; the 
cost to the electric company is very small. 

A correspondent states that the average rate was $3 ; the 
minimum charge was $2 per service and one hour's time for 
two men, use of apparatus and current, which included the 
time of moving from one job to another. If more time was 
consumed it was at the rate of $1.50 per hour. 

A correspondent states that the company charged a lump 
sum of $15 per house service, out of which it gave the licensed 
plumber 20 per cent for collecting and assuming all responsi- 
bilities, as to damage to pipes, et ccetera. 

A correspondent states that $25 per day was charged for 
the outfit, including the use of the team, wagon, driver and four 
linemen; also transformers, wire and other necessary appa- 
ratus; the current consumed was also included. The city sup- 
plied a policeman and a man detailed from the water-works. 



20 

A correspondent states : "We expect to derive considerable 
revenue from this source and will probably advertise a little. 
The outfit necessary for the operation consists of a horse and 
wagon, one experienced operator and one lineman. The force 
should be able to complete work inside of two hours after arriv- 
ing at the point of trouble. The cost of melting pipe, when 
done by the plumbers, varies from $10 to $50, depending upon 
how much bad luck they have had in working upon the wrong 
part of the pipe, and the time the customer is off from his 
service in some cases amounts to a week. Under these con- 
ditions we feel that the public will look favorably upon a charge 
of $10 for quick service." 

A correspondent gauges his price as follows: 

"For houses located on our mains, we charge $6 per single 
house and $10 for two houses. When they can be thawed out 
at one setting, where it is necessary to run the primaries two 
or three squares from the mains, we charge $10 for one and $15 
for two." One correspondent gives prices in lump sums for 
water mains ; this, I believe, is the only instance of the kind we 
have had. The charges for service pipes is $15 ; for a 4-inch 
main $50 and a 6-inch main $75. The length thawed for 
prices mentioned is not given. 

A correspondent states that his company charged $10 per 
service during the first part of the winter, but finally reduced the 
price to $5. At first the customers were very thankful, but 
later on thought the company made the money too easily, even at 
the reduced rate. He states further that it is not a line of busi- 
ness that is likely to be permanent, and while they would be 
willing at any time to accommodate the public, they did not think 
they would do any more of it, unless they had an assurance that 
the weather would be similar to that of last winter. 

In conclusion of Question 5, the reporter would state that 
nearly all of those who have used this method of thawing pipes 
have evidently made a large profit in the work, and are perfectly 
willing to provide the necessary equipment and to devote time and 
current in unlimited amounts so long as someone will pay the 
price, which, all things considered, can be a reasonable one and 
still leave a good margin of profit for the company doing the 
work. 



Question No. 6. In regard to measuring the current, but 
very few correspondents seem to have taken the trouble to make 
accurate measurements of the current. Usually an ammeter 
was placed in the primary, in order that the transformers might 
not be overloaded to such an extent as to cause them to be 
damaged. A few r used both an ammeter and a voltmeter, from 
which readings were kept and current figured on a volt-ampere 
basis. 

A correspondent used 15-ampere fuses in the primary, and 
as they were not blown he was satisfied that he did not use much 
over the amount mentioned. A correspondent states that the 
only way they could tell how much current they were using, 
was by the way the water boiled in the barrel used for the rheo- 
stat. 

A correspondent states as follows in reference to the meas- 
urement of current: "We find that the water always begins to 
flow before the lead pipe shows any appreciable heating. We 
intend, therefore, to dispense entirely with ammeters and instead 
to make use of the temperature of a piece of lead pipe filled 
with water, which will be inserted in the low-voltage circuit at 
the switch. Should the amperes in any particular case be twice 
as much as is needed — say 400 amperes instead of 200 amperes — 
I believe the only effect will be to shorten the time needed for 
melting the ice and starting the flow of water. The frozen pipe 
surrounded by earth at a temperature less than 32 degrees 
Fahrenheit can be regarded as a reservoir for heat, in which a 
certain quantity of heat must be generated and stored before 
melting takes place. If this heat is stored in half the time, the 
same temperature approximately will be attained in each case 
and it therefore makes no difference whether or not the current 
is increased abnormally, provided the time is correspondingly 
shortened. The only danger in passing an abnormally large 
current through the water pipe is when the excessive current is 
kept on until the pipe reaches a steady temperature, and the 
lead-pipe temperature indicator mentioned above will be an abso- 
lute measure of this." 

Question No. 7. All voltages from 2.5 to 500 seem to have 
been used. Only a few answers indicate that elaborate tests 
have been made. The majority of the work has been done, 
apparently, with little regard to the current consumption, the 



price charged being high enough to make up for any deficiency 
in this respect. From one correspondent we have the following : 

U A length of 40 feet of one-half inch lead pipe required 
186 amperes at 12 volts applied for five minutes. 

"For a length of 20 feet of half -inch extra heavy lead pipe, 
10 volts was required to force 150 amperes through, and from 
12 to 15 volts for 200 amperes. With a current of 200 amperes, 
the water was started in three minutes, but it was found 
necessary to raise the current to 281 amperes with a volt- 
age of 18 applied for 15 minutes. By this time the pipe 
was quite warm, the temperature being about 115 degrees 
Fahrenheit, which proved that there was no longer any 
ice in the pipe and that the flow of water was obstructed by other 
causes. One hundred feet of half-inch lead pipe required a 
pressure of 37 volts to force 270 amperes through ; time required, 
five minutes. In this case the current passed through 100 feet 
of water main. The actual kilowatts in this case were 7.5, 
which, for the space of five minutes, represents 0.62 kilowatt- 
hour. Another case of 60 feet of half-inch lead pipe in circuit 
with 60 feet of water main required 200 amperes at a voltage of 
ten for twenty minutes to free the pipe. The current consump- 
tion in this case was about 0.70 kilowatt-hour. One hundred 
feet of small service pipe, supposed to be of iron, required 200 
amperes at 25 volts for five minutes ; the current consumption 
being about 0.33 kilowatt-hour." 

A correspondent writes: "In one instance a street service 
was thawed, using storage batteries; the pressure was 2.12 volts, 
the amount of current used was not given." He stated further 
that the safe maximum current that can be carried by a one- 
inch lead pipe is 300 amperes. 

Question 7a. The alternating current seems to be used 
almost universally for this work, and in only one or two instances 
has the direct current been used. A correspondent states that 
in the use of direct current, he found that the energy would all 
be expended at or near the positive connection of the pipe, he 
having noticed that the ice had melted and the water boiled in 
the pipe at the positive connection while at the negative con- 
nection, three feet away, there was no indication of heat what- 
ever. He stated further that the alternating current was much 
more effiective than the direct current, and that he could accom- 



2 3 

plish more with less than one-half the amperes of alternating- 
current. In one instance he applied from 400 to 480 amperes 
at 104 volts direct-current to a 2-inch water main for six hours 
the first day and eight hours the next, making no impression 
whatever. After four or five days of very cold weather, he 
applied 150 amperes of the alternating current and thawed it 
out in about three hours. 

Referring to that portion in which the correspondent states, 
that in the use of direct current he finds the energy would 
all be expended at or near the positive connection, etc. — this 
seems hardly possible and might be due to several reasons; for 
instance, poor connection at the positive end, the pipe being 
exposed to the air only while the other end of the pipe might 
have been buried in the frost, or near some other substance 
that could rapidly conduct away the heat. 

Question No. 8. The water rheostat described in Question 
No. 8 evidently seems to have been used by about 90 per cent 
of those who have used this method of thawing pipes, because it 
was so easily obtained. In the majority of cases the work came 
upon all of us very unexpectedly, and it was a question of how 
quickly we could get ready, and not how complete an outfit we 
could devise for the purpose. In only a few instances has the 
water rheostat been used in the primary side. As a matter of 
safety, this would not seem advisable. Almost everything has 
been used for electrodes, from copper wire to railroad fish 
plates. Any metal with a sufficient area will answer the purpose. 
In a few instances choke coils have been used in the primaries 
of standard transformers, and in a small number of cases, no 
method whatever was used for controlling the current. 

One correspondent writes that he is operating a two-wire, 
1 10- volt, direct-current plant, which does not give any day 
service. To thaw service pipes, he connects one side of his 
system to the water main at his station. He then connects the 
other side of his circuit to the house service, having previously 
arranged with the engineer at the station to give the required 
amperes on the station ammeter. From a point of labor, this 
is probably the simplest method of thawing water pipes that has 
been used, but as the majority of central stations operate twenty- 
four hours a day, this plan would not be applicable. 

Question 9. Transformers of all descriptions were used. 



24 

Jn many cases they were taken from scrap piles, and put to 
good use thawing pipes. The secondary voltage seems about 
equally divided between 50 and 100 volts ; evidently because 
standard transformers were used and 50 volts in some instances 
not found enough, 100 was used, as it covered all cases, regard- 
less, however, of current consumption. In thawing lengths from 
100 to 200 feet of service pipes or of mains, the opinion seems 
to be that from 75 to 100 volts are necessary at times. The aver- 
age capacity of transformers used is about 15 kilowatts. 

Question 10. In reference to the purchase of a special 
transformer for this work, but few correspondents indicate that 
they would go to this expense. The majority think that the 
standard transformers are thoroughly practical, and that they 
have the advantage of being useful upon other work. One cor- 
respondent stated that if they were assured of sufficient work, 
they would purchase a special transformer made for this pur- 
pose, with a primary of 2300 and a secondary of 50 volts 
maximum, and a capacity of 25 kilowatts. They tried to induce 
the city to pay one-half of the purchase price of a transformer 
of this description, agreeing to furnish current for thawing 
street mains at a rate of $5 per house. The thawing proposition 
was favored by some members of the council, but they were 
unable to induce them to make the purchase. 

A correspondent states that he would advise the purchase 
cf a special transformer for this purpose, with a secondary 
voltage of 50-75 and 100. This arrangement of voltage, in con- 
nection with the water rheostat, he thought would take care of 
any case they might encounter. The capacity should be about 
20 kilowatts with an overload margin of 50 per cent for one- 
half hour. He could afford to pay about $250 for such an out- 
fit, and thought it advisable to induce the city to purchase or 
carry an investment of such a transformer to be used for this 
work and for it exclusively. 

A correspondent stated that if he were to purchase a special 
transformer for this purpose, he would have the secondary from 
o to 50 volts, having found that 30-kilowatt capacity is 
sufficient for all sizes of pipe up to two inches. A correspondent 
stated that he did not think it advisable to purchase a special 
transformer, as he might not use it for three or four years, neither 
should he try to induce the city water company to carry the in- 



25 

vestment, and cannot see why he should expect it to do so, 
as he proposes to charge a price for such work, so that he could 
readily afford to carry the investment himself. 

Question n. (Answered in the tabulated Schedule No. 2.) 

Special attachments for connecting wires to faucets or 
.mains seem to be used in only a few instances, the ordinary 
method being to wrap about 12 inches of the bare wire, used 
for the secondary, around the faucet or main. Regarding the 
handling of primary feeders, the majority of operators were 
particular to have them insulated, while a number allowed them 
to lie on the ground without special care other than to keep 
pedestrians and teams away from them. 

Question 12. The value of this method of thawing seems 
to be fully as much appreciated in the thawing of mains as in 
house service work. From the tabulated Schedule No. 2 an 
idea can be obtained as to the number that have thawed out 
mains of different sizes and lengths; also other information 
that may be desired. 

Question 13. But very little damage seems to have been 
•done to pipes in general from this method of thawing. In a 
few instances where the water did not start to flow through, 
the pipes being clogged, the lead pipes were melted off at the 
faucets. 

A correspondent states : "No damage was detected to service 
pipes or joints. In the first gas-service thaw, workmen failed 
to disconnect pipe from meter, and current found its way through 
a chain support of heating plant, causing chain to heat and char 
timber. No further trouble was experienced, for workmen were 
instructed to remove connections from meters and see that service 
pipes were free from water and heating pipes." 

Question 14. But very few companies evidently spent much 
money on a special rig for the conveyance of the transformer 
and other appliances. As a rule, they were placed in an ordinary 
wagon or sleigh. A rough skeleton switchboard was frequently 
built, upon which were placed the primary cutouts, switches and 
instruments. 

Question 15. The opinion of the correspondents is that 
the work is not hazardous if capable linemen are employed in 
the work. They all seem to agree, however, that a good profit — 



26 



some suggesting ioo per cent — should be made upon the labor 
employed. 

Question 16. In almost every case the efforts of the com- 
panies in this work were greatly appreciated by the city officials 
and the residents of their respective cities. Only in one or two 
instances do the correspondents state that the customers thought 
they made money too easily, while one stated that some of his 
customers thought they were being robbed, as usual. 



TABLE I 
DATA PERTAINING TO HOUSE SERVICES 





Service Pipe 








Time 








Amperes 


Volts 








Required 


Lengt 


h Kind 


Size 








60 fe 


et Iron 


2^-inch 


320 


no 


25 minutes 


80 ' 


' " 


X " 


300 


no 


23 


IOO ' 


( 41 


3/ " ' 


300 


no 


11 


90 • 


i It 


I " 


280 


no 


10 " 


150 ' 




I " 


280 


no 


2 hours 


130 ' 




i# " 


340 


no 


i# " 


150 ' 


Lead 


X " 


250 


50 


12 minutes 


240 ' 


Iron 


X " 


250 


52 


30 


300 ' 


1 1 1 


2 


250 


52 


2}4 hours 


250 ' 


' ' ' 


I " 


500 


50 


20 minutes 


700 ' 


' " 


I " 


175 


55 


5 hours 


250 * 


4 " 


K ' 


400 


50 


20 minutes 


IOO ' 




% ; 


135 


55 


10 




IOO ' 


1 44 


% " 


I50 


20 


45 




380 ' 


1 ". 


x ;; 


300 


30 


10 




150 ' 


( 14 




200 


40 


20 




50 ' 


« 44 


2 " 


500 


50 


120 




75 ' 


' '' 


X " 


IOO 


50 


5 




600 ' 


4 4. 


I " 


60 


50 


60 




200 ' 


4 44 


X " 


no 


50 


6 




60 ' 


» 44 


2 " 


160 


50 


4 




50 ' 


4 44 


% |§ 


250 


20 


5 




50 ' 


Lead 


% " 


250 


15 


5 




220 ' 


Iron 


1 " 


60 


105 


75 




180 • 


Lead 


* :; 


185 


35 


15 




45 ' 


Iron 




140 


220 


17 




IOO ' 


4 44 


1 " 


175 


220 


15 




200 ' 


4 44 


X " 


120 


5o 


1 




250 ' 


4 44 


X " 


120 


50 


10 




20 ' 


4 4 4 


2 


2,000 


6 


3 




70 ' 


4 4 4 


X " 


300 


16 


15 




250 ' 


4 4 4 


I " 


400 


50 


20 




40 ' 




X " 


300 


50 


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REGARDING THE THAWING OF GAS MAINS 

Only a few instances have been reported of successful 
thawing of gas-service pipes. A correspondent stated that their 
first attempt was on a gas service pipe, connected to a gas engine, 
which furnished power for a daily paper. Two plumbers had 
failed to open it in two days. The correspondent stated that they 
rigged up a temporary outfit and had a full head of gas flowing 
in fifteen minutes. The size of the pipe and amount of current 
was not given, 

A correspondent states that during the past winter he had 
thawed out a large number of 2 ^( -inch gas services and 
gas mains. No record of the current consumed was kept, but 
the time required was about two and one-half hours for each 
section of a 4-inch gas main, from 125 to 200 feet in length. He 
found that it was not practicable to undertake to thaw more than 
200 feet of 4-inch gas mains at one setting, and then with proper 
facilities given to remove the water from the mains. He does 
not believe that the thawing of gas mains is as hazardous as it 
first appears, but that exceptional care must be taken and the 
work done under the supervision of the superintendent of the 
gas service department and a competent electrician. 



PORTABLE OUTFIT 

A correspondent from one of our large cities states that they 
are contemplating the fitting up of a portable generator, driven 
by a gasolene engine, to be used in the out-of-town districts. 
A capacity of about 10 kilowatts giving 500 amperes at 20 
volts, or the equivalent in a higher voltage, would answer all 
purposes and an engine of ten horse-power would probably be 
sufficient. 

The "Auto Truck" shown in Figure 10 was later on fitted 
with a set of auxiliary batteries, which in connection with those 
on the auto were used with much success. With any portable 
outfit, the usual delay of finding and connecting to the nearest 
service is, of course, avoided. 

An instance is recorded of a 12-horse-power gas automobile 
being used, a 7-kw dynamo being mounted to the front portion 
of the vehicle, giving 600 amperes at 12 volts. 



3i 

In conclusion, your reporter wishes to extend personal 
thanks to all those who have contributed information for this 
article, and hopes that some good, at least, will be forthcoming 
and that all those who have not used this method of thawing 
pipes will try it if they have the opportunity, and that they may 
profit by the same to a reasonable extent. 

A word in reference to the prices charged : because a resident 
will pay a large amount to have a real necessity, like water, in 
the house is no reason why you should charge several hundred 
per cent profit. It is worth to any one ioo per cent above the 
cost to the electric company, to which amount the company is 
justly entitled for the use of apparatus, wear and tear of same, 
liability of accident, handling high voltages, and so forth. 

Electricity in any form should no longer be considered a 
luxury, and thawing pipes belongs as much to the electrical 
industry as does the heating of flat-irons, chafing-dishes, and 
other appliances, which are becoming so popular among our 
customers. 

Respectfully submitted, 

George S. Haley. 

Rutland, Vt., November, 1904. 



LIBRARY OF CONGRESS 

■UHHI 

021 218 289 



JAMBS KEMPSTER PRINT 






•Hz 



LIBRARY OF CONGRESS 



021 218 289 8 ft 



